U.S. Pat. No. 4,250,211 describes a paper coating apparatus having an applicator cooperating with a counter roll about which the paper is guided.
The applicator includes a main beam whose front side supports a rear wall which is mounted adjacent to and spaced from a front wall so as to define a chamber converging towards the roll. A doctor blade extends from the rear wall and engages the web to hold back excess coating material. At a distance from the blade is an orifice plate which is adjustably mounted on the front wall to be movable toward and away from the counter roll. To close and seal the chamber at its sides, end plates are provided engaging sealing ledges secured to the side of the applicator.
These lateral end plates are, however, not only provided to enclose the chamber in order to prevent leakage of coating color contained in the chamber, but also to limit the application of coating to a desired width of the web, i.e. to prevent a coating of the paper web along its edges. As practice has shown, this is disadvantageous as especially when changing the adjustment of the applicator, e.g. upon angular adjustments, the end plates move with the blade or blades and cannot guarantee proper sealing of the coating material chamber and at the same time present coating of the edges of the paper web and leakage past these edges.